My invention relates to the weaving of textiles having large continuous areas of a single color. My invention has particularly useful application to weaving processes for pile fabrics such as carpets and rugs, that can incorporate more than one color. The invention eliminates the undesirable streaking along the length of woven fabrics that frequently occurs when an off-color warp end is woven into a large single color area of the fabric. As used in the industry an "end" of yarn resents a continuous "length" of yarn.
Perhaps the single greatest unsatisfied need within the area rug industry today, and through the ages, is the construction of multicolored rugs having large uninterrupted areas of single colors. Border rugs and children's rugs, such as those illustrated in FIGS. 2 and 3 hereof, are typical of the type rug to which I am referring. Large uninterrupted areas are designated in FIGS. 2 and 3 as 10, 11, 12, and 13. There is a tremendous commercial potential if quality versions of these type rugs can be produced economically. Prior to the present invention a method had not been devised to adapt modern tufting or weaving techniques to produce quality versions of these type rugs economically.
Weaving and tufting, which are the two predominant means for manufacturing rugs, have until now been unable to produce quality versions of these rugs economically. Tufting machines have been unable to satisfy the commercial demand for these type rugs because, with the exception of a few commercially unproven tufting machines, tufting processes cannot produce rugs that change color along the length of the rug. While color can vary along the width of the rug, each row of tufts along the entire length of the rug must remain the same color.
Because there is a market for rugs that change color along their length, the tufting industry has for years attempted to develop a tufting machine with this capability. Tufting machines that employ more than one needle at each tufting position along the width of a rug, or that are capable of varying yarn types in individual needles during the tufting process, would conceivably be able to change colors along the length of the rug. Indeed, these type machines are well known in the art. For instance, Spanel, (U.S. Pat. No. 3,554,147) discloses a tufting machine wherein each needle is fed a tuft of yarn from one of three yarn positions before each tufting stroke. Kile (U.S. Pat. No. 4,549,496) discloses an invention embodying the same concept. Boyles (U.S. Pat. No. 3,172,380) discloses a tufting machine having a plurality of tandem arranged needles that are individually actuable at each tufting position. To my knowledge none of the foregoing inventions has proven able to economically produce the type rug with which my invention is concerned on a large scale, because they are too complex and impractical. Accordingly, it is the practice in the tufting industry, when it is desired to produce tufted border rugs of two solid colors, to mend four individual pieces of one color of rug to the exterior of another rug piece of another color, to form a rug similar to that shown in FIG. 2. This is a labor intensive, expensive method. Moreover, mending is impractical when the design of a rug is any more complicated than a border rug, such as children's rugs as in FIG. 3 with which my invention is also concerned.
Weaving looms are ideal for the construction of border rugs and children's rugs because of the ability of jacquard weaving looms and other weaving looms to incorporate many colors in a rug along the length of the rug according to any designated pattern. Indeed, the only limitation on the design a jacquard loom can create is the number of colors the loom can practically incorporate. Oriental design rugs, one of the most popular type rugs produced by the weaving process, exemplify the versatility and capabilities of weaving looms. FIG. 3 is a drawing of a woven rug that also illustrates this versatility. The weaving loom suffers from the drawback, however, that if an off-color end of yarn, or warp, is integrated into the fabric for a substantial distance, it will appear as an undesirable streak throughout its length. Along the width of a woven rug there are a multiplicity of warp ends integrated in lines through the entire length of the rug. Each end of yarn is pulled from a separate bobbin. In a rug having a large uninterrupted area of a single color, there are thus multiple ends of identically colored yarn woven side by side through the length of the large uninterrupted area. If one end of yarn is even slightly off color it will appear as a prevalent streak in the rug in contrast to the other yarns that surround it. It has been observed that the streak is most prevalent in bolder yarn colors such as navy blue and forest green, colors that are in popular demand today.
The streaking in woven rugs produced by discolored yarn is a problem of historic proportions in the weaving industry that, until my invention, had not yet been overcome. This problem has existed since rugs and other fabrics were first woven, which authorities date back to before the ancient Egyptian civilization. Warp ends incorporated into a rug can be off-color for many reasons, but the color of a warp end is a product generally of two factors: (1) the quality and color consistency of the fibers incorporated into the yarn; and (2) the texture and fiber distribution within individual yarn ends. Numerous patents are accordingly aimed at reducing the variability associated with these two factors. Ruggiero, et al. (U.S. Pat. No. 5,360,457), Kelly, et al. (U.S. Pat. No. 5,358,537), and Hemling, et al. (U.S. Pat. No. 5,120,326), for instance, each disclose methods for improving the yarn fiber dying process, for more consistently colored yarn fibers and yarn, ends. Kawanchi (U.S. Pat. No. 5,276,083), and Leons, et al. (U.S. Pat. Nos. 5,040,276 and 5,327,622), similarly disclose methods to produce consistently textured yarns. These inventions, among other technological advances, have improved the quality and color consistency of yarns and reduced the streaking problem with which my invention is concerned.
Despite these advances, however, yarn manufacture remains an inexact science, and off-color yarns are still frequently manufactured. For this reason other industry leaders have focused their resources to identify off color yarns before they are sold to textile manufacturers. Such inventions are disclosed and discussed, for instance, by Coons (U.S. Pat. No. 5,195,313), Hendrix, et al. (U.S. Pat. No. 3,929,013), and in "NTC is making quantum leaps in research projects", Textile World (May, 1994, Vol. 144, No. 5, p. 46). Even these efforts have not solved the streaking problem entirely, however, because even if every yarn end is perfectly color consistent before incorporation into a rug, an end of yarn can end up off-color once incorporated into the weave, because the texture (and hence color) of a yarn end is influenced by the tension with which it is pulled into a loom, and a loom pulls yarn ends from different bobbins at different tensions. Bobbins are pulled at different tensions because of a number of factors, including the angle from which the yarn ends are drawn into the loom, the manner in which the yarn ends are threaded into the loom, and even the amount of yarn that remains on a bobbin. Yarn ends drawn in a straight line, such as yarns 4a, 4b and 4c shown in FIG. 1, are drawn under less tension that other yarn ends. The yarn ends that are drawn at greater angles to the weaving loom are typically drawn under greater tensions, which tensions influence the texture of the yarn, and cause the yarn ends to become discolored.
Some inventions have been developed to equalize yarn tensions to reduce the yarn tension effect I have just described. Coons and Vickery (U.S. Pat. No. 5,221,059), for instance, disclose an apparatus to overcome this variable tension problem, that equilibrates component tensions in a multicomponent filamentary yarn of the type used in a weaving loom. This invention can be used principally during backwinding of bulked continuous filament yarn. Vandeweghe, et al. (U.S. Pat. No. 4,736,776) discuss the use of a mobile backrest to even out warp thread tension within the loom. As with all the other foregoing developments, however, these inventions suffer from their complexity, size, and capital expense. Coons and Vickery, and Vandeweghe, suffer from the additional fact that inconsistent color yarns woven with these devices are still colored inconsistently upon incorporation into the rug. To my knowledge, because of these impediments neither of these inventions has been integrated with a weaving loom to produce streakless rugs of the type with which my invention is concerned.
As the foregoing illustrates, many efforts have been made over the years to improve the consistency in the color of yarns manufactured, and to ensure that yarns having a high color consistency are not compromised by the weaving process. To my knowledge, however, manufacturers remain unable to produce perfectly color consistent yarns, and looms remain incapable of applying uniform tension to yarns and not discoloring yarns. Accordingly, the efforts by the weaving industry have failed to produce consistently streakless rugs, and weaving manufacturers remain unable to weave a color consistent rug in which a streak will not appear.
The weaving industry has accordingly devised several solutions to the streaking problem that simply work around it. Generally, rugs are designed and patterned, as in oriental rugs, so that one color does not travel in the face of the rug a significant distance, and so does not manifest itself as a streak if it is off color. If a manufacturer desires to produce a rug of one color in a large area, his choices have been either to manufacture such rugs with streaks or to incorporate other colors and designs into the large one color area to break up any streaks. FIG. 7 illustrates a typical children's rug manufactured according to this method, that incorporates in an alternating pattern dots throughout the rug that reduce the length any yarn end travels in the face of the rug. The pattern in FIG. 7 does not solve the streaking problem, and it does not enable weaving manufacturers to produce rugs with large single color areas that today are in commercial demand.
As the success of the tufting industry at selling border rugs produced by a second mending process demonstrates, a technique for producing woven rugs of the type I have described in a continuous mechanical loom would be commercially valuable. It is to this end that the present invention is directed.